Coffee-mill with electric driving device



.Julyy 5, 1932.

J. STOCKERT COFFEE MILL WITH ELECTRIC RIVINGl DEVICE Filed Aug. 15, 1930 22 z 19 22V l l 31 t 29 m s "2o aga 31 l /23 Y l 23/ NVENTOR,

A TTORNEY Patented July 5, 1932 UNITED STATES JOSEF STOKCKEBT, OF SCEVW'ELH, GERMANY, ASSIGNOB TO SIEMENS-SCHUCKEBTW'EBKE- PATENT OFFICE Ax'r1ENGEsnLLscHm,' or "BERLINfsmMENssrADm, GERMANY, A conroA'rIoN OF GERMANY COFFEE-MILL AWITH ELECTRIC DRIVING DEVICE appncauon'mea August 15, 1930, seriai'm.

The present invention refers to a coffeemill with an electric driving device'. The novelty of this invention is substantially, that the driving device consists of a magnetic system, provided with an oscillatin armature, whose coacting fixed poles are ocated outside the path of the armature, so that the armature canv swing /fieely past the poles. The transmission of motion from the swinging armature to the grinding device of the mill may be suitably carried out by a coaster clutch.

Such a driving device is superior to' an 0,1*-v dilnary electric motor, in thatthenumber of revolutions of the armature-shaft is smaller,n so that a saving of the expensive speed reduct-ion gearing required in the case of an may be'constructed in a very compact form.

In the accompanying drawing, showing how my invention may be reduced to prac-` tice- Fig. 1 represents a front view of the n'ovel coffee-mill;

FFig. 2 represents a section on line II-II, 1g. 1 Fig.3 represents a section on line IIL-III,

Fig. 2; j Fig. 4 represents an axial section through the grinding-cone on an enlarged scale; and

, Fig. 5 represents a front view of the grinding-cone at the same scale, the cover being removed to show the coaster clutch.

The coffee-mill as illustrated has a casing, consisting of two parts, (1 and 2) the back part (1) of which carries the electric driving device for the grinding device of 475,574, and-in Germany August 20,4929.

the min. The from; part (2), exea u, the back part (1) by the screws (3), houses the grinding device, consisting of a fixed hollow,

conical ring (4) and a cone (5) located in the' conical rmg.' Both the rotatable grindingcone (.5) and the fixed grinding-ring (4) areA provided with a coarse and a fine toothing on their. coacting grinding surfaces at the top,

the grinding-ring (4) lis provided with an opening (6), through which'the material to be ground is` fed .to the grindin surfaces from a funnel (7), placed on the ont part (2) of the casing. Below, the front part of the casing (2) has an outleto (8) throu h,

'which the ground material falls from t e grinding device (4, 5) into a container '(9), placed beneaththe outletl (8) the container (9) slides on its upper rejecting edge l(1Q) in two angular rails (11 and may easily be removed. The material entering the grinding-device (4, 5) tends to press the inding-cone (5) out of the grinding-'ring 4)V but this is prevented by an adjusting-screw (12) with knurled head (13) threaded into the front part of the casing; (2) which permits of an adjustment of the degree of neness 'of grinding, by bringing the grinding-cone (5) into 'closer or farther proximity of the grinding ring (4) The adjusting-screw (12) is secured against displacement by a small set screw (14) threaded i(nt)o the head (13) and supported on casing The grinding-cone (5) is driven through a coaster .clutch (1 5, 16)I by a shaft y(18) carried in two ball bearings (17 L The clutch i's built into the interior of the grinding-conel and protected by a cover (27) which closes p the cone opening, (26) and is attachable by screws (28). Shaft 18 is driven by a magnetic motor with oscillating armature arrangedin the rear casing portion (1). The

motor consists of. a U-shaped magnet made of'laminated iron, each of the opposing pole Shanks (20, 21) carrying an' exciting coil (22, 23). The ends of the Shanks are cylindrically concave and form the pole faces of the magnet. The armature (24) is mounted on shaft .18 and swings clear between the two 1w A provided at the under side of the front part of the casing (2),

(20, 21) of the magnet, thus imparting one direction of movement to the armature, while the magnetic pull imparts movement in the other direction. The two ball bearings of the armature-shaft (18) are mounted in two plates of vulcanized fibre (30, 31) fixed between the two magnet-coils (22, 23). One (31) of the two plates (30, 31) is provided with an extension, on which a stud (32) is arranged for supporting the other end of the spring (29), which acts on the armature (24). The casing of the mill (1, 2) together with the driving motor is fastened to a wooden panel (34) by means of screws (33),which permits convenient attachment of the mill to a wall.

The machine works in the following manner The motor of the mill is supplied with alternating current. In the position Fig. 3,

the armature (24) is positioned in line with the pole shoes (20,21) i. e. the magnetic fields between the momentarily opposing poles of the armaturel (24) and of the fixed magnet (19) are closed. At that time the spring (29) acting on the armature (24) is extended. At the next moment, the magnetic fields of the poles (20,21) of the fixed magnet (19) are reversed or opened byfthe alternating current, so that the armature (24) is drawn back by `the-spring (29). The direction in which the armature 4(24) recedes from the poles is compulsory in consequence of the spring (29), which draws the armature constantly in one and the same direction. The backward and forward motion of the armature (24) is transmitted by the armature-shaft and coaster clutch (15, 16) to the grinding-cone (5),

which performs a rotary movement only 1n one direction, in consequence of the employment of this type of clutch. In combination with the grinding-ring (4) the grindingcone (5) grinds the material falling 1n through the opening (6) in the grindingring (4), and introduced through the funnel (7). After the grinding is effected, the finely ground material escapes between the. grinding-cone and ring and is caught in the container (9).

If the material'is to be ground finer, it is only necessary to loosen the small screw (14) and' turn the set-screw (12) clockwise, so that the grinding-cone (5) is inserted a little farther into the cone-shaped hollow of the ,g,'rindingringY (4) .then the material between-the cone and the ring will be finer.

When the desired degree of fineness has been attained, the set-screw (12) is fixed by tightening the screwA (14).

Naturally, the invention is not limited to the illustrated example, but other constructions are also possible. More especially, the motor may in certain cases be driven by intermittent continuous current, as the equivalent of valternating current, sol far as the present invention is concerned.

I claim:

1. In an electrically driven coffee-mill, in combination a magnetic motor having fixed field poles, cnergizable by alternating operating current. an armature disposed betweenA said poles to freely swing past them, a spring connected to said armature and disposed to counteract the attractive forces exerted by said poles, whereby said armature oscillates past said poles, a rotary grinding element and; a coaster clutch for coupling said element with said armature for step by stepl operation of said grinding element in grinding direction.

x 2. In an electrically driven coffee-mill, in combination a magnetic motor having fixed field poles, energiza-ble by alternating operating current, an armature disposed'between said poles to freely swing past them, a spring connected to said armature and disposed to counteract the attractive forces exerted by said poles,A whereby said armature oscillates past said poles, a rotary grinding element and a coaster clutch housed within said element for coupling said grinding element with said armature for step by step operation of said grinding element in grinding direction. l i

In testimony whereof I afiix my signature.

^ JOSEF STOCKERT.

y grindingl 

